Gas turbine engines typically include a fan delivering air into a compressor. The air is compressed in the compressor and delivered into a combustion section where it is mixed with fuel and ignited. Products of this combustion pass downstream over turbine blades, driving them to rotate. Turbine rotors, in turn, drive the compressor and fan rotors. A turbine section typically includes multiple stages of vanes and rotor blades used to extract a maximum amount of energy from the combustion flow. The efficiency of the engine is impacted by ensuring that the products of combustion pass in as high a percentage as possible across the turbine blades.
With each new engine design, gas temperatures increase and cooling flow requirements decrease. This requires cooling flow to be utilized in a more efficient manner and flow distribution to be tailored to prevent overcooling in certain regions. Because of radial gas temperature profiles, trailing edges of airfoils are a region where cooling flow distribution could be tailored and overall flow reduced. However, current cast trailing edges are already at the minimum area required to prevent core break during the casting process and thus do not allow a reduction or redistribution of flow. One option would be to replace cast trailing edge slots with drilled filmholes to allow a redistribution and reduction of cooling flow. However, this presents manufacturing challenges in the casting process resulting in an undesirable increase in variation of core position and wall thicknesses.